Prosthetic heart valves, scaffolding structures, and systems and methods for implantation of same

ABSTRACT

Prosthetic valves and their component parts are described, as are prosthetic valve delivery devices and methods for their use. The prosthetic valves are particularly adapted for use in percutaneous aortic valve replacement procedures. The delivery devices are particularly adapted for use in minimally invasive surgical procedures.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/066,124, filed Feb. 25, 2005 now U.S. Pat. No. 7,785,341, and whichclaims the benefit of U.S. Provisional Application Ser. No. 60/548,731,entitled “Foldable Stent for Minimally Invasive Surgery,” filed Feb. 27,2004, and U.S. Provisional Application Ser. No. 60/559,199, entitled“Method and Multiple Balloon for Percutaneous Aortic ValveImplantation,” filed Apr. 1, 2004, each of which are fully incorporatedherein by reference.

FIELD OF THE INVENTION

The present invention relates generally to medical devices and methods.More particularly, the present invention relates to prosthetic heartvalves, structures for providing scaffolding of body lumens, and devicesand methods for delivering and deploying these valves and structures.

BACKGROUND OF THE INVENTION

Diseases and other disorders of the heart valve affect the proper flowof blood from the heart. Two categories of heart valve disease arestenosis and incompetence. Stenosis refers to a failure of the valve toopen fully, due to stiffened valve tissue. Incompetence refers to valvesthat cause inefficient blood circulation by permitting backflow of bloodin the heart.

Medication may be used to treat some heart valve disorders, but manycases require replacement of the native valve with a prosthetic heartvalve. Prosthetic heart valves can be used to replace any of the nativeheart valves (aortic, mitral, tricuspid or pulmonary), although repairor replacement of the aortic or mitral valves is most common becausethey reside in the left side of the heart where pressures are thegreatest. Two primary types of prosthetic heart valves are commonlyused, mechanical heart valves and prosthetic tissue heart valves.

The caged ball design is one of the early mechanical heart valves. Thecaged ball design uses a small ball that is held in place by a weldedmetal cage. In the mid-1960s, another prosthetic valve was designed thatused a tilting disc to better mimic the natural patterns of blood flow.The tilting-disc valves had a polymer disc held in place by two weldedstruts. The bileaflet valve was introduced in the late 1970s. Itincluded two semicircular leaflets that pivot on hinges. The leafletsswing open completely, parallel to the direction of the blood flow. Theydo not close completely, which allows some backflow.

The main advantages of mechanical valves are their high durability.Mechanical heart valves are placed in young patients because theytypically last for the lifetime of the patient. The main problem withall mechanical valves is the increased risk of blood clotting.

Prosthetic tissue valves include human tissue valves and animal tissuevalves. Both types are often referred to as bioprosthetic valves. Thedesign of bioprosthetic valves are closer to the design of the naturalvalve. Bioprosthetic valves do not require long-term anticoagulants,have better hemodynamics, do not cause damage to blood cells, and do notsuffer from many of the structural problems experienced by themechanical heart valves.

Human tissue valves include homografts, which are valves that aretransplanted from another human being, and autografts, which are valvesthat are transplanted from one position to another within the sameperson.

Animal tissue valves are most often heart tissues recovered fromanimals. The recovered tissues are typically stiffened by a tanningsolution, most often glutaraldehyde. The most commonly used animaltissues are porcine, bovine, and equine pericardial tissue.

The animal tissue valves are typically stented valves. Stentless valvesare made by removing the entire aortic root and adjacent aorta as ablock, usually from a pig. The coronary arteries are tied off, and theentire section is trimmed and then implanted into the patient.

A conventional heart valve replacement surgery involves accessing theheart in the patent's thoracic cavity through a longitudinal incision inthe chest. For example, a median sternotomy requires cutting through thesternum and forcing the two opposing halves of the rib cage to be spreadapart, allowing access to the thoracic cavity and heart within. Thepatient is then placed on cardiopulmonary bypass which involves stoppingthe heart to permit access to the internal chambers. Such open heartsurgery is particularly invasive and involves a lengthy and difficultrecovery period.

A less invasive approach to valve replacement is desired. Thepercutaneous implantation of a prosthetic valve is a preferred procedurebecause the operation is performed under local anesthesia, does notrequire cardiopulmonary bypass, and is less traumatic. Current attemptsto provide such a device generally involve stent-like structures, whichare very similar to those used in vascular stent procedures with theexception of being larger diameter as required for the aortic anatomy,as well as having leaflets attached to provide one way blood flow. Thesestent structures are radially contracted for delivery to the intendedsite, and then expanded/deployed to achieve a tubular structure in theannulus. The stent structure needs to provide two primary functions.First, the structure needs to provide adequate radial stiffness when inthe expanded state. Radial stiffness is required to maintain thecylindrical shape of the structure, which assures the leaflets coaptproperly. Proper leaflet coaption assures the edges of the leaflets mateproperly, which is necessary for proper sealing without leaks. Radialstiffness also assures that there will be no paravalvular leakage, whichis leaking between the valve and aorta interface, rather than throughthe leaflets. An additional need for radial stiffness is to providesufficient interaction between the valve and native aortic wall thatthere will be no valve migration as the valve closes and holds full bodyblood pressure. This is a requirement that other vascular devices arenot subjected to. The second primary function of the stent structure isthe ability to be crimped to a reduced size for implantation.

Prior devices have utilized traditional stenting designs which areproduced from tubing or wire wound structures. Although this type ofdesign can provide for crimpability, it provides little radialstiffness. These devices are subject to “radial recoil” in that when thedevice is deployed, typically with balloon expansion, the final deployeddiameter is smaller than the diameter the balloon and stent structurewere expanded to. The recoil is due in part because of the stiffnessmismatches between the device and the anatomical environment in which itis placed. These devices also commonly cause crushing, tearing, or otherdeformation to the valve leaflets during the contraction and expansionprocedures. Other stenting designs have included spirally wound metallicsheets. This type of design provides high radial stiffness, yet crimpingresults in large material strains that can cause stress fractures andextremely large amounts of stored energy in the constrained state.Replacement heart valves are expected to survive for many years whenimplanted. A heart valve sees approximately 500,000,000 cycles over thecourse of 15 years. High stress states during crimping can reduce thefatigue life of the device. Still other devices have included tubing,wire wound structures, or spirally wound sheets formed of nitinol orother superelastic or shape memory material. These devices suffer fromsome of the same deficiencies as those described above. The scaffoldingstructures and prosthetic valves described herein address bothattributes of high radial stiffness along with crimpability, andmaximizing fatigue life.

SUMMARY OF THE INVENTION

The present invention provides apparatus and methods for deployingsupport structures in body lumens. The methods and apparatus areparticularly adapted for use in percutaneous aortic valve replacement.The methods and apparatus may also find use in the peripheralvasculature, the abdominal vasculature, and in other ducts such as thebiliary duct, the fallopian tubes, and similar lumen structures withinthe body of a patient. Although particularly adapted for use in lumensfound in the human body, the apparatus and methods may also findapplication in the treatment of animals.

In one aspect of the invention, a prosthetic valve is provided. Theprosthetic valve includes a support member and a valvular body attachedto the support member. The prosthetic valve has an expanded state inwhich the support member has a cross-sectional shape that is generallycylindrical or generally oval and which has a first cross-sectionaldimension (e.g., diameter), and a contracted state in which the supportmember has a second cross-sectional dimension (e.g., diameter) smallerthan the first. The prosthetic valve is in its contracted state duringdelivery of the prosthetic valve to a treatment location, and in itsexpanded state after deployment at the treatment location. Preferably,the cross-sectional dimension of the support member in its expandedstate is sufficiently large, and the support member possesses sufficientradial strength, to cause the support member to positively physicallyengage the internal surface of the body lumen, such as the aortic valveannulus or another biologically acceptable aortic position (e.g., alocation in the ascending or descending aorta), thereby providing astrong friction fit.

Specifically, in several preferred embodiments, the support member has across-sectional dimension that is slightly larger than the dimension ofthe treatment location, such as a body lumen. For example, if thetreatment location is the root annulus of the aortic valve, the supportmember may be provided with a cross-sectional dimension that is fromabout 0 to about 25% larger than the cross-sectional dimension of thevalve annulus. Cross-sectional dimensions even larger than 25% greaterthan that of the body lumen may also be used, depending upon the natureof the treatment location. As described in more detail below, oncedeployed, the support member extends to its full cross-sectionaldimension—i.e., it does not compress radially due to the radial forceimparted by the lumen or other tissue. Rather, the support member willexpand the cross-sectional dimension of the lumen or other tissue at thetreatment location. In this way, the support member reduces thepossibility of fluid leakage around the periphery of the device. Inaddition, due to the strength of the interference fit that results fromthe construction of the device, the support member will have properapposition to the lumen or tissue to reduce the likelihood of migrationof the device once deployed.

In several embodiments, the support member is a structure having atleast two peripheral segments, at least two of which segments areconnected to each other by a foldable junction. As used herein, the term“segment” refers to a constituent part into which the support member isdivided by foldable junctions or other junctions connecting adjacentsegments. In several embodiments, each segment comprises a panel, withtwo or more connected panels making up the support member.Alternatively, and without intending to otherwise limit the descriptionsprovided, segments may comprise beams, braces, struts, or otherstructural members extending between the foldable junctions provided onthe support member. Any of these (or any other) alternative structures,or any combinations thereof, may be provided as one or more segments ofthe support member.

In the above embodiments of the support member, the foldable junctionmay comprise any structural member that allows two adjacent segments topartially or completely fold one upon another. In several preferredembodiments, the foldable junction comprises a hinge. Suitable hingesinclude mechanical hinges, membrane hinges, living hinges, orcombinations of such hinges.

In addition to the foldable junctions, two adjacent panels may beconnectable by a selectively locking junction, such as pairs of opposedtabs and slots. In embodiments that include three or more segments, acombination of foldable junctions and locking junctions may be used.

The support structure may be provided with one or more anchoring membersthat are adapted to engage the internal wall of the body lumen. Eachanchoring member may comprise a barb, a tooth, a hook, or any othermember that protrudes from the external surface of the support structureto physically engage the internal wall of the body lumen. Alternatively,the anchoring member may comprise an aperture formed in the supportstructure that allows tissue to invaginate therethrough, i.e., theoutward radial force of the support member against the vessel wallcauses the frame portion of the support member to slightly embed intothe vessel wall, thereby causing some of the tissue to penetrate throughthe aperture into the interior of the support member. The tissueinvagination acts to anchor the support structure in place. An anchoringmember may be selectively engageable, such as by an actuator, or it maybe oriented so as to be permanently engaged. Alternatively, theanchoring member may be self-actuating, or it may be deployedautomatically during deployment of the support member.

The anchoring member advantageously may perform functions in addition toengaging the internal wall of the body lumen. For example, the anchoringmember may ensure proper positioning of the support structure within thebody lumen. It may also prevent migration or other movement of thesupport structure, and it may provide additional or enhanced sealing ofthe support structure to the body lumen, such as by creating bettertissue adherence.

The support structure may also be provided with an optional sealingmember, such as a gasket. The sealing member preferably is fixed to theexternal surface of the support structure around all or a portion of thecircumference of the support structure, and serves to decrease oreliminate the flow of fluids between the vessel wall and the supportmember. The sealing member may comprise a relatively soft biocompatiblematerial, such as a polyurethane or other polymer. Preferably, thesealing member is porous or is otherwise capable of expanding orswelling when exposed to fluids, thereby enhancing the sealing abilityof the sealing member. The sealing member may include a functionalcomposition such as an adhesive, a fixative, or therapeutic agents suchas drugs or other materials.

As an additional option, a coating may be applied to or created on anyof the surfaces of the support member. Coatings may be applied orcreated to provide any desired function. For example, a coating may beapplied to carry an adhesive, a fixative, or therapeutic agents such asdrugs or other materials. Coatings may be created on the externalsurface of the support member to facilitate tissue penetration (e.g.,ingrowth) into the support structure. Coatings may also be provided topromote sealing between the support member and the native tissue, or toreduce the possibility that the support member may migrate from itsintended location. Other coating functions will be recognized by thoseskilled in the art.

The valvular body may be of a single or multi-piece construction, andincludes a plurality of leaflets. The valvular body may be attachedeither to the internal or external surface of the support structure. Inthe case of a single-piece construction, the valvular body includes abase portion that is attachable to the support structure, and aplurality of (and preferably three) leaflets extending from the baseportion. In the case of a multi-piece construction, the valvular bodyincludes a plurality of (preferably three) members, each including abase portion that is attachable to the support structure and a leafletportion. In either case, the base portion(s) of the valvular body areattached to a portion of the internal or external surface of the supportstructure, and the leaflets extend away from the base portion andgenerally inwardly toward each other to form the valve.

The valvular body, either single-piece or multi-piece, may comprise ahomogeneous material, for example, a polymer such as polyurethane orother suitable elastomeric material. Alternatively, the valvular bodymay comprise a coated substrate, wherein the substrate comprises apolymer (e.g., polyester) or metallic (e.g., stainless steel) mesh, andthe coating comprises a polymer such as polyurethane or other suitableelastomeric material. Other suitable constructions are also possible.

Alternatively, the valvular body may comprise human (including homograftor autograft) or animal (e.g., porcine, bovine, equine, or other)tissue.

The valvular body may be attached to the support structure by anysuitable mechanism. For example, an attachment lip formed of a polymer,fabric, or other flexible material may be molded or adhered to thesurface of the support member, and the valvular body sewn, adhered, ormolded onto the attachment lip. Alternatively, an edge portion of thevalvular body may be sandwiched between a pair of elastomeric stripsthat are attached to the surface of the support member. Other andfurther attachment mechanisms may also be used.

As described above, each of the foregoing embodiments of the prostheticvalve preferably has a fully expanded state for deployment within a bodylumen, and a contracted state for delivery to the lumen in a minimallyinvasive interventional procedure through the patient's vasculature. Inthe fully expanded state, each of the segments of the support member isoriented peripherally and adjacent to one another, attached to eachadjacent segment by a foldable junction or an locking junction. In thecontracted state, the segments are folded together at the foldablejunctions and, preferably, then formed into a smaller diameter tubularstructure. The contracted state may be achieved in differentcombinations and manners of folding and rolling the segments andjunctions, depending on the particular structure of the prostheticvalve.

For example, in one embodiment, the prosthetic valve comprises agenerally cylindrical support member made up of three panels, with eachpanel connected to its adjacent panel by a hinge. The hinges may bemechanical hinges, membrane hinges, living hinges, or a combination ofsuch hinges. In its fully expanded state, each panel of the prostheticvalve is an arcuate member that occupies approximately 120°, or onethird, of the circular cross-section of the cylindrical support member.Alternatively, one or more of the panels may span a smaller portion ofthe cylindrical support member, while the other panel(s) are relativelylarger. For example, a relatively shorter panel may be provided on aside of the valve corresponding to the non-coronary native valveleaflet, which is generally smaller than the other native valveleaflets. A valvular body is attached to the internal surface of each ofthe three panels. The contracted state is obtained by first invertingeach of the panels at its centerline, i.e., changing each panel from aconvex shape to a concave shape by bringing the centerline of each paneltoward the longitudinal axis running through the center of the generallycylindrical support member. This action causes the foldable junctions tofold, creating a vertex at each foldable junction. For the foregoingthree panel support member, a three vertex star-shaped structureresults. In the case of a four panel support member, a four vertexstar-shaped structure would result. The valvular body, which is formedof generally flexible, resilient materials, generally follows themanipulations of the support member without any substantial crimping,tearing, or permanent deformation.

Inversion of the panels results in a structure having a relativelysmaller maximum transverse dimension than that of the fully expandedstructure. To further reduce the transverse dimension, each vertex iscurled back toward the central axis to create a plurality of lobesequi-spaced about the central axis, i.e., in the three-panel structure,three lobes are formed. The resulting multi-lobe structure has an evenfurther reduced maximum transverse dimension, and represents oneembodiment of the contracted state of the prosthetic valve.

In another embodiment, the prosthetic valve comprises a generallycylindrical support member made up of three panels defining threejunctions, two of which comprise hinges, and one of which comprises aset of locking tabs and slots. The hinges may be mechanical hinges,membrane hinges, living hinges, other hinge types, or a combination ofsuch hinges. As with the prior embodiment, in its fully expanded state,each panel of the prosthetic valve is an arcuate member that occupiesapproximately 120°, or one third, of the circular cross-section of thecylindrical support member. A valvular body is attached to the internalsurface of each of the three panels, with at least one separation in thevalvular body corresponding with the location of the locking junction onthe support member. The contracted state in this alternative embodimentis obtained by first disengaging the locking tabs and slots at thenon-hinge junction between a first two of the panels. Alternatively, thelocking tabs and slots may be simply unlocked to permit relative motionwhile remaining slidably engaged. The third panel, opposite thenon-hinge junction, is then inverted, i.e., changed from convex toconcave by bringing the centerline of the panel toward the longitudinalaxis running through the center of the generally cylindrical supportmember. The other two panels are then nested behind the third panel,each retaining its concave shape, by rotating the hinges connecting eachpanel to the third panel. The resulting structure is a curved-panelshaped member. The valvular body, which is formed of generally flexible,resilient materials, generally follows the manipulations of the supportmember without any substantial crimping, tearing, or permanentdeformation. The structure is then curled into a tubular structurehaving a relatively small diameter in relation to that of the fullyexpanded prosthetic valve, and which represents an alternativeembodiment of the contracted state of the prosthetic valve.

In still another embodiment, the prosthetic valve comprises a generallyoval-shaped support member made up of two panels, with a hinge providedat the two attachment edges between the panels. The hinges may bemechanical hinges, membrane hinges, living hinges, or a combination ofsuch hinges. A valvular body is attached to the internal surface of eachof the two panels. The contracted state is obtained by first invertingone of the two panels at its centerline, i.e., changing the panel from aconvex shape to a concave shape by bringing the centerline of the paneltoward the longitudinal axis running through the center of the generallyoval support member. This action causes the foldable junctions to fold,creating a vertex at each foldable junction, and causes the two panelsto come to a nested position. The valvular body, which is formed ofgenerally flexible, resilient materials, generally follows themanipulations of the support member without any substantial crimping,tearing, or permanent deformation. The structure is then curled into atubular structure having a relatively small diameter in relation to thatof the fully expanded prosthetic valve, and which represents anotheralternative embodiment of the contracted state of the prosthetic valve.

Several alternative support members are also provided. In one suchalternative embodiment, the support structure is a generally tubularmember constructed such that it is capable of transforming from acontracted state having a relatively small diameter and large length, toan expanded state having a relatively large diameter and small length.The transformation from the contracted state to the expanded stateentails causing the tubular member to foreshorten in length whileexpanding radially. The forced foreshortening transformation may beachieved using any of a wide range of structural components and/ormethods. In a particularly preferred form, the support structurecomprises an axially activated support member. The axially activatedsupport member includes a generally tubular body member formed of amatrix of flexible struts. In one embodiment, struts are arranged incrossing pairs forming an “X” pattern, with the ends of a first crossingpair of struts being connected to the ends of a second crossing pair ofstruts by a band connector, thereby forming a generally cylindricalmember. Additional generally cylindrical members may be incorporatedinto the structure by interweaving the struts contained in theadditional cylindrical member with one or more of the struts included inthe first cylindrical member. An axial member is connected to at leasttwo opposed band connectors located on opposite ends of the structure.When the axial member is decreased in length, the support member isexpanded to a large diameter state, accompanied by a degree offoreshortening of the support member. When the axial member is increasedin length, the support member is contracted to a smaller diameter state,accompanied by a degree of lengthening of the support member. Theexpanded state may be used when the support member is deployed in a bodylumen, and the contracted state may be used for delivery of the device.A valvular body, as described above, may be attached to the internal orexternal surface of the support member.

In the foregoing embodiment, the axial member may be replaced by acircumferential member, a spirally wound member, or any other structureadapted to cause the tubular member to foreshorten and thereby totransform to the expanded state. The axial or other member may beattached to opposed connectors, to connectors that are not opposed, orconnectors may not be used at all. Alternatively, the support member maybe formed of a plurality of braided wires or a single wire formed into atubular shape by wrapping around a mandrel. In either case, thestructure is caused to radially expand by inducing foreshortening.

As a further alternative, the support structure (or portions thereof)may be self-expanding, such as by being formed of a resilient or shapememory material that is adapted to transition from a relatively longtubular member having a relatively small cross-sectional dimension to arelatively shorter tubular member having a relatively largercross-sectional dimension. In yet further alternatives, the supportstructure may partially self-expand by foreshortening, after which anexpansion device may be used to cause further radial expansion andlongitudinal foreshortening.

In another alternative embodiment, the support member comprises amultiple panel hinged ring structure. The multiple panel hinged ringstructure includes a plurality of (preferably three) circumferentialrings interconnected by one or more (preferably three) longitudinalposts. Each ring structure, in turn, is composed of a plurality ofsegments, such as curved panels, each connected to its adjacent panelsby a junction member, such as a polymeric membrane hinge. The hinges arerotated to transform the structure from an expanded state fordeployment, to a contracted state for delivery. A valvular body, asdescribed elsewhere herein, is attached to the internal or externalsurface of the support member.

In still another alternative embodiment, the support member comprises acollapsing hinged structure. The collapsing hinged structure includes aplurality of (preferably about twenty-four) panels arranged peripherallyaround the generally tubular structure, each panel having a tab on itsedge that overlaps and engages a mating tab on the opposed edge of theadjacent panel, interlocking the adjacent panels. An elastic membrane isattached to an external surface of adjacent panels and provides a forcebiasing the adjacent panels together to assist the tabs in interlockingeach adjacent pair of panels. Preferably, the elastic membrane isattached to the main body of each panel, but not at the opposed edges.Thus, the tabs may be disengaged and the panels rotated to form a vertexat each shared edge, thereby defining a multi-vertex “star” shape thatcorresponds with the contracted state of the support member. The supportmember is transformed to its expanded state by applying an outwardradial force that stretches the elastic membrane and allows the tabs tore-engage. A valvular body, as described elsewhere herein, is attachedto the internal or external surface of the support member.

The various support members may be incorporated in a prosthetic valve,as described above, by attaching a valvular body to the external orinternal surface of the support member. In the alternative, any of theforegoing support members may be utilized without a valvular body toprovide a support or scaffolding function within a body lumen, such as ablood vessel or other organ. For example, the multi-segment,multi-hinged support member may be used as a scaffolding member for thetreatment of abdominal aortic aneurisms, either alone, or in combinationwith another support member, graft, or other therapeutic device. Othersimilar uses are also contemplated, as will be understood by thoseskilled in the art.

Each of the foregoing prosthetic valves and support members is adaptedto be transformed from its expanded state to its contracted state to becarried by a delivery catheter to a treatment location by way of aminimally invasive interventional procedure, as described more fullyelsewhere herein.

In other aspects of the invention, delivery devices for delivering aprosthetic valve to a treatment location in a body lumen are provided,as are methods for their use. The delivery devices are particularlyadapted for use in minimally invasive interventional procedures, such aspercutaneous aortic valve replacements. The delivery devices include anelongated delivery catheter having proximal and distal ends. A handle isprovided at the proximal end of the delivery catheter. The handle may beprovided with a knob, an actuator, a slider, other control members, orcombinations thereof for controlling and manipulating the catheter toperform the prosthetic valve delivery procedure. A retractable outersheath may extend over at least a portion of the length of the catheter.Preferably, a guidewire lumen extends proximally from the distal end ofthe catheter. The guidewire lumen may extend through the entire lengthof the catheter for over-the-wire applications, or the guidewire lumenmay have a proximal exit port closer to the distal end of the catheterthan the proximal end for use with rapid-exchange applications.

The distal portion of the catheter includes a carrier adapted to receiveand retain a prosthetic valve and to maintain the prosthetic valve in acontracted state, and to deploy the prosthetic valve at a treatmentlocation within a body lumen. In one embodiment, the distal portion ofthe catheter is provided with a delivery tube having a plurality oflongitudinal slots at its distal end, and a gripper having alongitudinal shaft and a plurality of fingers that extend longitudinallyfrom the distal end of the gripper. Preferably, the delivery tube hasthe same number of longitudinal slots, and the gripper includes the samenumber of fingers, as there are segments on the prosthetic valve to bedelivered. The longitudinal slots on the distal end of the delivery tubeare equally spaced around the periphery of the tube. Similarly, asviewed from the distal end of the gripper, the fingers are arranged in agenerally circular pattern. For example, in the case of three fingers,all three are spaced apart on an imaginary circle and are separated fromeach other by approximately 120°. In the case of four fingers, thefingers are separated from each other by approximately 90°, and so on.The spacing and orientation of the longitudinal slots and fingers mayvary from these preferred values while still being sufficient to performthe delivery function in the manner described herein. The gripper isslidably and rotatably received within the delivery tube, and thedelivery tube is internal of the outer sheath. The outer sheath isretractable to expose at least the longitudinal slots on the distalportion of the delivery tube. The gripper is able to be advanced atleast far enough to extend the fingers distally outside the distal endof the delivery tube.

In alternative embodiments of the above delivery device, the gripperfingers may comprise wires, fibers, hooks, sleeves, other structuralmembers extending distally from the distal end of the gripper, orcombinations of any of the foregoing. As described below, a primaryfunction of the fingers is to retain a prosthetic valve on the distalend of the gripper, and to restrain segments of the support member ofthe valve in an inverted state. Accordingly, any of the above (or other)structural members able to perform the above function may be substitutedfor the fingers described above.

An optional atraumatic tip or nosecone may be provided at the distal endof the device. The tip is preferably formed of a relatively soft,elastomeric material and has a rounded to conical shape. A central lumenis provided in the tip to allow passage of the guidewire. The shape andphysical properties of the tip enhance the ability of the deliverydevice to safely pass through the vasculature of a patient withoutdamaging vessel walls or other portions of the anatomy. In addition, theatraumatic tip may enhance the ability of the distal portion of thedevice to cross the native heart valve when the leaflets of the nativevalve are fully or partially closed due to calcification from disease orother disorder.

The delivery device is particularly adapted for use in a minimallyinvasive surgical procedure to deliver a multi-segment prosthetic valve,such as those described above, to a body lumen. To do so, the prostheticvalve is first loaded into the delivery device. In the case of aprosthetic valve having a three segment support member, the deliverytube will have three longitudinal slots at its distal end, and thegripper will be provided with three fingers. The prosthetic valve isloaded into the delivery device by first inverting the three segments toproduce a three vertex structure. Inverting of the prosthetic valvesegments may be performed manually, or with the aid of a tool. Theprosthetic valve is then placed onto the distal end of the gripper,which has been previously extended outside the distal end of thedelivery tube, with each of the three fingers retaining one of theinverted segments in its inverted position. The gripper and fingers,with the prosthetic valve installed thereon, are then retracted backinto the delivery tube. During the retraction, the gripper and fingersare rotationally aligned with the delivery tube such that the threevertices of the prosthetic valve align with the three longitudinal slotson the distal end of the delivery tube. When the gripper and fingers arefully retracted, each of the three vertices of the prosthetic valveextends radially outside the delivery tube through the longitudinalslots. The gripper is then rotated relative to the delivery tube (or thedelivery tube rotated relative to the gripper), which action causes eachof the folded segments of the prosthetic valve to engage an edge of itsrespective delivery tube slot. Further rotation of the gripper relativeto the delivery tube causes the folded segments to curl back toward thelongitudinal axis of the prosthetic valve internally of the deliverytube, creating three lobes located fully within the delivery tube. Theprosthetic valve is thereby loaded into the delivery device. The outersheath may then be advanced over the distal portion of the catheter,including the delivery tube, to prepare the delivery device for use.

The prosthetic valve is delivered by first introducing a guidewire intothe vascular system and to the treatment location of the patient by anyconventional method, preferably by way of the femoral artery.Optionally, a suitable introducer sheath may be advanced to facilitateintroduction of the delivery device. The delivery catheter is thenadvanced over the guidewire to the treatment location. The outer sheathis then retracted to expose the delivery tube. The gripper is thenrotated relative to the delivery tube (or the delivery tube rotatedrelative to the gripper), thereby causing the folded segments of theprosthetic valve to uncurl and to extend radially outward through thelongitudinal slots of the delivery tube. The delivery tube is thenretracted (or the gripper advanced) to cause the prosthetic valve(restrained by the fingers) to advance distally out of the deliverytube. The gripper is then retracted relative to the prosthetic valve,releasing the prosthetic valve into the treatment location. Preferably,the inverted segments then revert to the expanded state, causing thevalve to lodge against the internal surface of the body lumen (e.g., theaortic valve root or another biologically acceptable aortic position).Additional expansion of the prosthetic valve may be provided, if needed,by a suitable expansion member, such as an expansion balloon or anexpanding mesh member (described elsewhere herein), carried on thedelivery catheter or other carrier.

In another embodiment of the delivery device, the distal portion of thecatheter includes a restraining sheath, an orientation sheath, aplurality of grippers, an expander, and a plurality of struts. Anoptional atraumatic tip or nosecone, as described above, may also befixed to the distal end of the device. Each of the grippers includes awire riding within a tube, and a tip at the distal end of the tube. Thewire of each gripper is adapted to engage the vertex of a prostheticvalve support member having multiple segments, and to selectivelyrestrain the prosthetic valve in a contracted state. The expander isadapted to selectively cause the grippers to expand radially outwardlywhen it is actuated by the user by way of an actuator located on thehandle.

The prosthetic valve may be loaded into the delivery device bycontracting the prosthetic valve (either manually or with a tool) byinverting each panel and then attaching each vertex to a respectivegripper on the delivery device. The grippers receive, retain, andrestrain the prosthetic valve in its contracted state. The gripperassembly having the prosthetic valve installed is then retracted intoeach of the orientation sheath and the restraining sheath to prepare thedevice for insertion into the patient's vasculature. The device is thenadvanced over a guidewire to a treatment location, such as the baseannulus of the native aortic valve or another biologically acceptableaortic position (e.g., a location in the ascending or descending aorta).The restraining sheath is then retracted to allow the prosthetic valveto partially expand (e.g., to about 85% of its full transversedimension), where it is constrained by the orientation sheath. Theprosthetic valve is then finally positioned by manipulation of thegrippers, after which the orientation sheath is retracted and thegrippers released. The prosthetic valve then is fixedly engaged in thetreatment location.

In yet another embodiment of the delivery device, the distal portion ofthe catheter includes one or more restraining tubes having at least one(and preferably two) adjustable restraining loops. The restrainingtube(s) extend distally from a catheter shaft out of the distal end ofthe delivery device, and each restraining loop is a wire or fiber loopthat extends transversely from the restraining tube. Each restrainingloop is a flexible loop capable of selectively restraining a contractedprosthetic valve. The restraining loop may be selectively constricted orreleased by a control member, such as a knob, located on the handle ofthe device, or by another external actuation member. An optionalretractable outer sheath may be provided to cover the distal portion ofthe catheter. Additionally, an optional atraumatic tip or nosecone, asdescribed above, may be provided at the distal end of the device.

The prosthetic valve may be loaded onto the delivery device bycontracting the prosthetic valve (either manually or with a tool) intoits contracted state, for example, by inverting each panel and curlingeach inverted panel into a lobe. The contracted prosthetic valve is thenplaced onto the restraining tube(s) and through the one or morerestraining loops. The loops are constricted around the contractedprosthetic valve, thereby restraining the prosthetic valve in itscontracted state. The optional outer sheath may then be advanced overthe prosthetic valve and the restraining tube(s) to prepare the deliverydevice for use. The device is then advanced over a guidewire to atreatment location, such as the base annulus of the native aortic valveor another biologically acceptable aortic position (e.g., a location inthe ascending or descending aorta). The restraining sheath is thenretracted to expose the contracted prosthetic valve. The restrainingloops are released, such as by rotating the control knob, therebyreleasing the prosthetic valve and allowing it to self-expand. Theprosthetic valve is thereby fixedly engaged in the treatment location.An expansion member may be advanced to the interior of the prostheticvalve (or retracted from distally of the valve) and expanded to provideadditional expansion force, if needed or desired.

In each of the foregoing device delivery methods, the user is able todeploy the device in a careful, controlled, and deliberate manner. Thisallows the user to, among other things, pause the delivery procedure andreposition the device if needed to optimize the delivery location. Thisadded degree of control is a feature that is not available in many ofthe previous percutaneous device delivery methods.

In another aspect of the invention, an expansion member is provided forperforming dilation functions in minimally invasive surgical procedures.For example, the expansion member may be used in procedures such asangioplasty, valvuloplasty, stent or other device placement orexpansion, and other similar procedures. In relation to the devices andmethods described above and elsewhere herein, the expansion member maybe used to provide additional expansion force to the support membersused on the prosthetic valves described herein.

In one embodiment, the expansion member comprises a plurality ofinflation balloons oriented about a longitudinal axis. Each inflationballoon is connected at its proximal end by a feeder lumen to a centrallumen that provides fluid communication between the inflation balloonsand a source of inflation media associated with a handle portion of acatheter. The central lumen itself is provided with a guidewire lumen toallow passage of a guidewire through the expansion member. A flexiblemember is attached to the distal end of each of the inflation balloons,and also includes a guidewire lumen. In a preferred embodiment, theexpansion member includes three inflation balloons, although fewer ormore balloons are possible. The balloons may each be inflatedindividually, all together, or in any combination to obtain a desiredforce distribution. The multiple inflation balloon structure provides anumber of advantages, including the ability to provide greater radialforces than a single balloon, and the ability to avoid occluding avessel undergoing treatment and to allow blood or other fluid to flowthrough the device.

In an alternative embodiment, the expansion member comprises a flexible,expandable mesh member. The expandable mesh member includes a shaft anda cylindrical woven mesh member disposed longitudinally over the shaft.A distal end of the cylindrical mesh member is attached to the distalend of the shaft. The proximal end of the cylindrical mesh member isslidably engaged to the shaft by a collar proximally of the distal end.As the collar is advanced distally along the shaft, the body of thecylindrical mesh member is caused to expand radially, thereby providinga radially expansion member. Alternatively, the proximal end of the meshmember may be fixed to the shaft and the distal end may have a collarengagement allowing it to advance proximally along the shaft to causethe mesh member to expand radially. Still further, each of the proximaland distal ends of the mesh member may be slidably engaged to the shaft,and each moved toward the other to cause radial expansion.

Other aspects, features, and functions of the inventions describedherein will become apparent by reference to the drawings and thedetailed description of the preferred embodiments set forth below.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a prosthetic valve in accordance withthe present invention.

FIG. 1B is a perspective view of a support member in accordance with thepresent invention.

FIG. 2A is a perspective view of a support member having illustratinginverted panels.

FIG. 2B is a top view of the support member of FIG. 2A.

FIG. 2C is a top view of a support member in a contracted state.

FIG. 3A is a perspective view of another support member in accordancewith the present invention.

FIG. 3B is a close-up view of a hinge on the support member of FIG. 3A.

FIG. 3C is a close-up view of an locking tab and slot on the supportmember of FIG. 3A.

FIG. 3D is a perspective view of the support member shown in FIG. 3A,illustrating inversion of a panel.

FIG. 3E is a perspective view of the support member shown in FIG. 3A,illustrating a nested arrangement of the three panels.

FIG. 3F is a perspective view of the support member shown in FIG. 3A,illustrating a contracted state of the support member.

FIG. 3G is an end view of the support member shown in FIG. 3A,illustrating a contracted state of the support member.

FIG. 3H is a top view of another support member, illustrating a nestedarrangement of the three panels.

FIG. 3I is a side view of the support member shown in FIG. 3H.

FIG. 4A is a perspective view illustrating a hinge connecting two panelsof a support member.

FIG. 4B is a perspective view of the hinge shown in FIG. 4A,illustrating the hinge in is folded state.

FIG. 4C is a perspective view of another hinge connecting two panels ofa support member.

FIG. 4D is a perspective view of another hinge connecting two panels ofa support member.

FIG. 5A is a perspective view of a support member having invertedpanels, illustrating removable hinge pins.

FIG. 5B is a perspective view of a support member after separation ofits three panels.

FIG. 6 is a perspective view of another support member.

FIG. 7 is a close-up view of an attachment mechanism for attaching avalvular body to a support member.

FIG. 8A is a perspective view of a valvular body.

FIG. 8B is a perspective view showing separate leaflets of the valvularbody of FIG. 8A.

FIG. 9A is a perspective view of an axially activated support member inits contracted state.

FIG. 9B is a perspective view of the axially activated support member ofFIG. 9A, shown in its expanded state.

FIG. 10A is a perspective view of a multiple panel hinged ringprosthetic valve.

FIG. 10B is an end view of the prosthetic valve shown in FIG. 10A.

FIG. 10C is a perspective view of a multiple panel hinged ring supportmember.

FIG. 10D is an end view of the support member shown in FIG. 10C.

FIG. 10E is a close-up view of a panel contained on the support membershown in FIG. 10C.

FIG. 10F is a perspective view of a portion of a ring of panelscontained on the support member shown in FIG. 10C.

FIG. 10G is a top view of a ring of panels contained on a supportmember, shown in a contracted state.

FIG. 10H is a perspective view of the support member shown in FIG. 10C,shown in the contracted state.

FIG. 10I is a top view of a ring of panels contained on another supportmember, shown in a contracted state.

FIG. 10J is a perspective view of the support member shown in FIG. 10I,shown in the contracted state.

FIG. 11A is a perspective view of a collapsing hinged support member,shown in its expanded state.

FIG. 11B is a perspective view of the collapsing hinged support member,shown in its contracted state.

FIG. 11C is a close-up view of a portion of the collapsing hingedsupport member shown in FIG. 11A.

FIG. 12A is a perspective view of a prosthetic valve retained on adelivery device.

FIG. 12B is a top view of the prosthetic valve and delivery device shownin FIG. 12A.

FIG. 12C is a side view of the prosthetic valve and delivery deviceshown in FIG. 12A.

FIG. 12D is another top view of the prosthetic valve and delivery deviceshown in FIG. 12A.

FIG. 12E is another top view the prosthetic valve and delivery deviceshown in FIG. 12A.

FIG. 12F is another top view of the prosthetic valve and delivery deviceshown in FIG. 12A.

FIG. 13A is a perspective view, shown in partial cross-section, of aprosthetic valve delivery device.

FIG. 13B is a close-up view of a portion of the prosthetic valvedelivery device shown in FIG. 13A.

FIG. 13C is another close-up view of a portion of the prosthetic valvedelivery device shown in FIG. 13A

FIG. 13D is another perspective view, shown in partial cross-section, ofthe prosthetic valve delivery device shown in FIG. 13A.

FIG. 13E is an illustration showing the delivery device of FIG. 13Adelivering a prosthetic valve to a treatment location.

FIG. 14A is a perspective view of another prosthetic valve deliverydevice.

FIG. 14B is a close-up view of a distal portion of the prosthetic valvedelivery device shown in FIG. 14A.

FIG. 14C is another close-up view of the distal portion of theprosthetic valve delivery device shown in FIG. 14A.

FIG. 14D is an illustration showing the delivery device of FIG. 14Adelivering a prosthetic valve to a treatment location.

FIG. 14E is another illustration showing the delivery device of FIG. 14Adelivering a prosthetic valve to a treatment location.

FIG. 15A is a perspective view of another prosthetic valve deliverydevice.

FIG. 15B is a close-up view of a distal portion of the prosthetic valvedelivery device shown in FIG. 15A.

FIG. 16A is a perspective view of another prosthetic valve deliverydevice.

FIG. 16B is another perspective view of the prosthetic valve deliverydevice shown in FIG. 16A.

FIG. 17A is a perspective view of a multi-balloon expansion device.

FIG. 17B is another perspective view of the multi-balloon expansiondevice shown in FIG. 17A.

FIG. 18A is a perspective view of an expandable mesh member, shown inits contracted state.

FIG. 18B is another perspective view of the expandable mesh member ofFIG. 18A, shown in its expanded state.

FIG. 18C is an illustration showing the expandable mesh member beingadvanced into the interior space of a prosthetic valve.

FIG. 18D is another illustration showing the expandable mesh memberbeing advanced into the interior space of a prosthetic valve.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the present invention is described, it is to be understood thatthis invention is not limited to particular embodiments described, assuch may, of course, vary. It is also to be understood that theterminology used herein is for the purpose of describing particularembodiments only, and is not intended to be limiting, since the scope ofthe present invention will be limited only by the appended claims.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which these inventions belong. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present invention, the preferredmethods and materials are now described. All publications mentionedherein are incorporated herein by reference to disclose and describe themethods and/or materials in connection with which the publications arecited.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include plural referents unless thecontext clearly dictates otherwise.

The publications discussed herein are provided solely for theirdisclosure prior to the filing date of the present application. Nothingherein is to be construed as an admission that the present invention isnot entitled to antedate such publication by virtue of prior invention.Further, the dates of publication provided may be different from theactual publication dates which may need to be independently confirmed.

As will be apparent to those of skill in the art upon reading thisdisclosure, each of the individual embodiments described and illustratedherein has discrete components and features which may be readilyseparated from or combined with the features of any of the other severalembodiments without departing from the scope or spirit of the presentinventions.

A. Prosthetic Valves and Related Apparatus

Turning first to FIG. 1A, an embodiment of a prosthetic valve is shown.The prosthetic valve 30 is particularly adapted for use as a replacementaortic valve, but may be used for other indications as well. As shown,the prosthetic valve 30 includes a generally cylindrical support member32 and a valvular body 34 attached to the internal surface of thesupport member. Although a generally cylindrical support member isshown, support members having other than circular cross-sectionalshapes, such as oval, elliptical, or irregular, may also be provideddepending upon the nature of the treatment location and environment inwhich the prosthetic valve or the support structure are intended to beused.

The support member in the embodiment shown in FIG. 1A is made up ofthree generally identical curved panels 36, with each panel spanningapproximately 120° of the circular cross-section of the support member.(As noted elsewhere herein, the panels need not be generally identicalin terms of size, materials, thickness, or other properties.) Each panel36 includes a frame 38 and a semi-circular aperture 40 extending over alarge portion of the central portion of the panel. The aperture 40includes a number of interconnecting braces 42 extending across thebreadth of the aperture, thereby defining a number of sub-apertures 44between the braces. The braces define several diamond-shapedsub-apertures 46, partial diamond-shaped sub-apertures 48, and anelongated sub-aperture 50. Apertures and sub-apertures of differentshapes and sizes than those shown in the FIG. 1A embodiment are alsopossible. For example, in the alternative support member embodimentshown in FIG. 1B, a single semi-circular aperture 40 is provided, withno braces and no sub-apertures. Alternatively, a panel may comprise asolid member having no apertures or sub-apertures.

The panels of the support member are typically the portion of thestructure that engages the internal surface of the lumen at thetreatment location. In the case of a prosthetic heart valve, among otherfunctions, the panels physically engage and displace the leaflets of thenative valve. The panels are also the primary portion of the structurethat is in physical engagement with the body lumen and that is holdingthe structure in place and preventing migration. Therefore, thematerials and structure of the panels are adapted, at least in part, toperform these functions. In some instances, a large aperture may bepreferred, in other cases a particular bracing structure may bepreferred, while in still other cases it is preferable not to have anyapertures or bracing. These features may be varied to provide desiredperformance, depending upon the anatomical environment.

Each of the panels shown, and those described elsewhere herein, ispreferably formed from a sheet of resilient, biocompatible material,such as stainless steel, other metals or metal alloys, resilientpolymers such as plastics, or other suitable materials conventionallyused for implantable medical devices. In a preferred embodiment, thepanels are formed from a super-elastic shape-memory material, such asnitinol or other similar metal alloys. The panels may be molded,extruded, etched, cut, stamped or otherwise fabricated from sheets ofmaterial, or manufactured in other ways known to those skilled in theart.

Although the support member embodiment shown in FIG. 1A includes threepanels, those skilled in the art will recognize that fewer or morepanels may be incorporated into the support member. For example, a twopanel structure may be employed, or structures having four, five, ormany more panels. Alternatively, a structure may be provided havingnon-panel segments, such as beams, braces, struts, or other structuralmembers extending between the foldable junctions provided on the supportmember. Any of these (or any other) alternative structures, or anycombinations thereof, may be provided as one or more segments of thesupport member, provided that the structure is capable of providing thephysical and structural characteristics needed to support the prostheticvalve in its intended function.

In addition, although each of the segments making up a support membermay be identical to the other segments, it is also possible to providesegments having different physical properties. For example, in amulti-panel support member, the panels may be made up of differentmaterials, or one or more panels may have a different size or thicknessthan the other panel(s), or the physical properties between thedifferent panels may be altered in some other manner. This may be done,for example, as an accommodation for the treatment location in which theprosthetic valve is to be placed. The wall thickness of the aortic root,for example, varies around its circumference. Thus, desirable resultsmay be obtained by providing a support member having a first panel thatprovides greater structural strength (or resistance to collapse) thanthe other panels. Other variations are also possible.

Turning again to FIG. 1A, a hinge 52 is provided at the junction formedbetween each pair of adjacent panels. In the embodiment shown in FIG.1A, the hinge is a membrane hinge comprising a thin sheet of elastomericmaterial 54 attached to the external edge 56 of each of a pair ofadjacent panels 36. In the expanded state of the support member, asshown in FIG. 1A, the membrane hinge maintains the side-to-sideorientation of each pair of adjacent panels, preventing any significantamount of slipping or sliding between the panels. As described morefully below, the hinge 52 is also foldable so as to allow the panels 36to invert and the edges 56 to fold together to form a vertex. Theability of the hinge (or other foldable junction member) to allowadjacent panels to invert and fold against each other at adjacent edgesis a substantial feature in creating a contracted state for the supportmember, and the prosthetic valve. In addition, the hinge 52 (or otherfoldable junction) preferably is adapted to allow the support member 32to physically conform to the internal surface of the body lumen at thetreatment location.

As noted below and elsewhere, various types of hinges and other foldablejunctions may be used in alternative embodiments. For example, andwithout intending to otherwise limit the descriptions contained herein,other types of hinges that may be used include standard piano hinges,living hinges, and other types of mechanical hinges. See, for example,the support member 32 shown in FIG. 1B, in which each pair of adjacentpanels 36 is connected by a standard piano hinge 58, i.e., a long,narrow hinge with a pin 60 running the entire length of its joint thatinterconnects meshed sets of knuckles 62 formed on the edge of each ofthe pair of adjacent panels 36. Several other alternative hingestructures are shown in FIGS. 4A-D, in which FIGS. 4A-B show anothermembrane hinge in which the elastomeric strip 54 is attached to each ofa pair of adjacent panels 36 on the internal surface of the supportmember 32. FIG. 4A shows a portion of the support structure 32 in itsexpanded state, and FIG. 4B shows the portion of the structure after thepair of adjacent panels 36 have been folded against each other at themembrane hinge 52, thereby forming a vertex 64. FIG. 4C shows a close-upview of another standard piano hinge 58 design, similar to that shown inFIG. 1B, showing the pin 60 and the meshing knuckles 62 formed on theedge of each of the pair of adjacent panels 36. FIG. 4D shows a livinghinge 66 that includes a flexible (e.g., elastomeric) hinge member 68that is attached to each of the pair of adjacent panels 36 and thatextends the length of the junction between the panels. In addition, FIG.5A shows another support member (in a partially contracted condition)illustrating removable hinge pins.

Several alternative foldable junctions may also be used instead ofhinges. For example, a section of a sheet may be etched, scored, orotherwise thinned relative to the adjacent portions of the device toprovide a weakened section that allows inversion and folding of a pairof adjacent segments of the sheet, thereby providing a foldablejunction. Other alternative foldable junctions are also contemplated,and will be understood by persons of skill in the art, to be suitablefor use in the support members described herein.

Optionally, the foldable junction may be provided with a lock-outfeature that allows the foldable junction to fold in a direction thatallows adjacent panels to invert, as described herein, but that preventsthe foldable junction from folding in the opposite direction. Forexample, a standard piano hinge may be constructed in a manner thatprovides only about 180° of rotation in a conventional manner, andattached to a pair of adjacent panels such that inward rotation isallowed, but outward rotation is prevented. Other suitable lock-outmechanisms may be possible, as will be recognized by those of skill inthe art.

In addition, although the hinges and other foldable junctions arepreferably oriented uniformly vertically (i.e., parallel to thelongitudinal axis of the support member) on the periphery of the supportmember, other orientations are possible. For example, the hinges may beoriented horizontally (i.e., transverse) relative to the longitudinalaxis, they may be oriented diagonally relative to the longitudinal axis,they may have a zig-zag or spiral orientation, or they may take on anygeometric or irregular pattern.

Returning again to FIG. 1A, the valvular body 34 of the embodiment shownin the figure is a flexible artificial tissue multi-leaflet structure.The artificial tissue includes a unitary polymer material or a compositeof polymer overlaid onto a flexible substrate, which may be in the formof a mesh. The polymer material is any suitable flexible, biocompatiblematerial such as those conventionally used in implantable medicaldevices. Preferably, the polymer material is polyurethane or anotherthermoplastic elastomer, although it is not limited to such materials.The material comprising the flexible mesh is preferably a flexible,shear-resistant polymeric or metallic material, such as a polyester orvery fine metallic (e.g., stainless steel) mesh. The valvular body isdescribed more fully below in relation to FIGS. 8A-B.

In other embodiments, the valvular body may be formed of human tissue,such as homografts or autografts, or animal tissue, such as porcine,bovine, or equine tissue (e.g., pericardial or other suitable tissue).The construction and preparation of prosthetic tissue valvular bodies isbeyond the scope of the present application, but is generally known tothose of skill in the art and is readily available in the relevanttechnical literature.

The prosthetic valves described herein have an expanded state that theprosthetic valve takes on when it is in use. The FIG. 1A illustrationshows a prosthetic valve 30 in its expanded state. In the expanded stateof the prosthetic valve, the support member is fully 32 extended in itscylindrical (or alternative) shape, with each hinge 52 (or otherfoldable junction) in its extended, or non-folded state. As describedpreviously, in the expanded state, the support member 32 preferably hasa cross-sectional dimension (e.g., diameter) that is from about 0 toabout 25% larger than that of the body lumen or other treatmentlocation. Once deployed, the support member extends to its fullcross-sectional dimension—i.e., it does not compress radially due to theradial force imparted by the lumen or other tissue. Rather, the supportmember will expand the cross-sectional dimension of the lumen or othertissue at the treatment location. In this way, the support memberreduces the possibility of fluid leakage around the periphery of thedevice. In addition, due to the strength of the interference fit thatresults from the construction of the device, the support member willhave proper apposition to the lumen or tissue to reduce the likelihoodof migration of the device once deployed. The present prosthetic valvesalso have a contracted state that is used in order to deliver theprosthetic valve to a treatment location with the body of a patient. Thecontracted state generally comprises a state having a smaller transversedimension (e.g., diameter) relative to that of the expanded state. Thecontracted states of several of the prosthetic valve embodimentsdescribed herein are discussed below.

Turning to FIGS. 2A-C, a method for transforming a prosthetic valve fromits expanded state to its contracted state is illustrated. These Figuresshow a three-panel support member without a valvular body attached. Themethod for contracting a full prosthetic valve, including the attachedvalvular body, is similar to that described herein in relation to thesupport member alone.

As shown in FIGS. 2A-B, each of the panels 36 is first inverted, bywhich is meant that a longitudinal centerline 80 of each of the panelsis forced radially inward toward the central longitudinal axis 82 of thesupport member. This action is facilitated by having panels formed of athin, resilient sheet of material having generally elastic properties,and by the presence of the hinges 58 located at the junction betweeneach pair of adjacent panels 36. During the inversion step, the edges 56of each of the adjacent pairs of panels fold upon one another at thehinge 58. The resulting structure, shown in FIGS. 2A-B, is athree-vertex 64 star shaped structure. Those skilled in the art willrecognize that a similar procedure may be used to invert a four (ormore) panel support member, in which case the resulting structure wouldbe a four- (or more) vertex star shaped structure.

The prosthetic valve 30 may be further contracted by curling each of thevertices 64 of the star shaped structure to form a multi-lobe structure,as shown in FIG. 2C. As shown in that Figure, each of the three vertices64 is rotated toward the center longitudinal axis of the device, causingeach of the three folded-upon edges of the adjacent pairs of panels tocurl into a lobe 84. The resulting structure, illustrated in FIG. 2C, isa three-lobe structure that represents the fully contracted state of theprosthetic valve. Manipulation and use of the fully contracted device isdescribed more fully below. Those skilled in the art will recognize thata similar procedure may be used to fully contract a four (or more) panelsupport member, in which case the resulting structure would be a four-(or more) lobed structure.

In the case of a two panel support member, the support member may becontracted by first inverting one of the two panels to cause it to comeinto close relationship with the other of the two panels to form anested panel structure. The pair of nested panels is then rolled into asmall diameter tubular member, which constitutes the contracted state ofthe two-panel support member.

Turning to FIGS. 3A-I, another embodiment of a support member suitablefor use in a prosthetic valve is shown. This embodiment is structurallysimilar to the preceding embodiment, but is capable of being transformedto a contracted state in a different manner than that described above.The embodiment includes three panels 36, each having a semi-circularaperture 40. A standard piano hinge 58 is provided at two of thejunctions between adjacent pairs of panels. (See FIG. 3B). The thirdjunction does not have a hinge, instead having a locking member 90. Inthe embodiment shown, the locking member includes a tab 92 attached toeach of the top and bottom portions of the edge of the first 36 a of apair of adjacent panels, and a slot 94 provided along both the top andbottom edges of the second 36 b of the pair adjacent panels. (See FIG.3C). The tabs 92 on the first panel 36 a are able to extend through andride in the slots 94 on the second panel 36 b, thereby allowing thefirst panel 36 a to slide relative to the second panel 36 b whileremaining physically engaged to the panel, and then to slide back to theoriginal position. A locking tab 96 may be provided on the second panel36 b to selectively lock the first panel tab 92 in place in the slot 94.

FIGS. 3D-G illustrate the manner in which the preceding support memberis transformed to its contracted state. As shown in FIG. 3D, the panel36 c situated opposite the locking junction 90 is inverted while leavingthe other two panels 36 a-b in their uninverted state. The tabs 92 onthe first panels 36 a are then slid along the slots 94 in the secondpanel 36 b, causing the first and second panels 36 a-b to come into anested arrangement behind the inverted panel 36 c, with the first panel36 a nested between the inverted panel 36 c and the second panel 36 b.(See FIG. 3E). The nested panels are then able to be curled into arelatively small diameter tubular member 98, as shown in FIGS. 3F and3G, which constitutes the contracted state of the support member.

FIGS. 3H-I illustrate a similar support member in its partiallycontracted state in which the three panels 36 a-c are in the nestedarrangement. The support member shown in FIGS. 3H-I also include aplurality of brace members 42 extending through the aperture 40, formingdiamond-shaped sub-apertures 46, partial diamond-shaped sub-apertures48, and an elongated sub-aperture 50. A plurality of raised surfaces100, or bumps, are provided over the surfaces of each of the panels 36a-c to provide positive spacing for the valvular body 34 when theprosthetic valve 30 is placed in the contracted state. The positivespacing provided by the raised surfaces 100 serve to decrease thepossibility of squeezing, crimping, folding, or otherwise damaging thevalvular body 34 or its constituent parts when the prosthetic valve iscontracted. The raised surfaces 100 (or other spacing member) of thesupport member may be used on any of the embodiments of the prostheticvalves described herein.

Turning to FIGS. 5A-B, as described above, FIG. 5A illustrates a supportmember 32 having three panels 36 a-c and three standard piano hinges 58at the junctions between the three panels. The support member is shownwith each of its three panels 36 a-c in the inverted position. Each ofthe piano hinges 58 has a removable hinge pin 60. When the hinge pins 60are removed, the panels 36 a-c may be separated from each other, asillustrated in FIG. 5B. The ability to separate the panels may be usedto facilitate surgical (or other) removal of the support member, or theprosthetic valve, or the panels may need to be separated for anotherpurpose. Although piano hinges with removable hinge pins are shown inFIGS. 5A-B, alternative removable hinge structures may also be used. Forexample, a membrane hinge having a tearable membrane strip willfacilitate removal of the support member. Further alternatives mayinclude melting or unzipping a hinge. Other removable hinge structuresare also contemplated. In each of these cases, provision of a hinge thatmay be easily defeated by some mechanism creates that ability for theuser to more easily remove or otherwise manipulate a prosthetic valve orsupport member for any desired purpose.

FIG. 6 shows another embodiment of a support member 32 suitable for usein a prosthetic valve 30. The support member 32 includes three panels 36a-c, each panel having an elongated aperture 50 and a semi-circularaperture 40. The support member includes an elastomeric strip 54 at thefoldable junction between each pair of adjacent panels, each of whichforms a membrane hinge. A valvular body attachment lip 104 is attachedto the interior surface of each of the panels 36 a-c to facilitateattachment of the valvular body 34 to the support member 32. Theattachment lip 104 may comprise a polymer material suitable for sewing,adhering, or otherwise attaching to the valvular body. The attachmentlip 104 is preferably molded or adhered onto the interior surface ofeach of the panels of the support member. Although the attachment lip104 facilitates one method for attaching the valvular body to thesupport member, it is not the only method for doing so, and use of theattachment lip 104 is optional.

FIG. 7 illustrates another structure and method used to attach thevalvular body to the support member panels. A first strip 110 ofpolymeric material is adhered to the interior surface of the edge 56 ofeach panel. The first strip 110 of polymeric material does not need toextend along the entire edge, but generally about half of the length.The first strip 110 is adhered with any suitable adhesive material, orit may be molded directly onto the panel 36. An attachment lip 120formed on the base portion of the valvular body is then attached to eachof the first strips 110 of polymeric material. The attachment lips 120may be formed on the base portion of the valvular body 34 in any of theembodiments described below, including those having a unitary structureor those having a composite structure. (A composite structure is shownin FIG. 7). The attachment lips 110 may be attached to the strips ofpolymeric material using any suitable adhesive or any other suitablemethod. Next, and optionally, a second strip 112 of polymer material maybe attached to the exposed surface of the valvular body attachment lip120, sandwiching the attachment lip 120 between the first 110 and secondstrips 112 of material.

FIGS. 8A-B show perspective views of valvular bodies suitable for use inthe prosthetic valves described herein. The valvular body 34 shown inFIG. 8A is of a unitary construction, while that shown in FIG. 8B is ofa composite construction, including three separate leaflets 35 a-c.Turning first to the unitary structure embodiment shown in FIG. 8A, thevalvular body 34 includes a generally cylindrical base portion 122 thatthen contracts down into a generally concave portion 124 (as viewed fromthe interior of the valvular body). The valvular body 34 has three linesof coaptation 126 formed on the bottom of the concave portion 124. Aslit 128 is either cut or molded into each of the lines of coaptation126 to create three valve leaflets 130 that perform the valvular fluidregulation function when the valve is implanted in a patient. Anoptional attachment lip 120 may be formed on the outward facing lines ofcoaptation 126, to facilitate attachment of the valvular body 34 to thesupport member in the manner described above in relation to FIG. 7.

Turning to the composite structure embodiment shown in FIG. 8B, eachseparate leaflet 35 a-c includes a base portion 132 and a generallyconcave portion 134 extending from the base. Each leaflet 35 a-c alsoincludes a pair of top edges 136 and a pair of side edges 138. The topedges and side edges of each leaflet 35 a-c are positioned against thetop edges and side edges of each adjacent leaflet when the compositestructure embodiment is attached to an appropriate support member.

As described above, in either the unitary or composite constructionembodiments, the valvular body may be formed solely from a singlepolymer material or polymer blend, or it may be formed from a substratehaving a polymer coating. The materials suitable for use as the polymer,substrate, or coating are described above. Alternatively, the valvularbody may comprise human or animal tissue.

The valvular body may be attached to the support member by any suitablemethod. For example, the valvular body may be attached to the supportmember by sewing, adhering, or molding the valvular body to anattachment lip, as described above in relation to FIG. 6. Or, thevalvular body may be attached to the support member using the attachmentstrips described above in relation to FIG. 7. Alternatively, thevalvular body may be adhered directly to the support member using anadhesive or similar material, or it may be formed integrally with thesupport member. Other and further suitable attachment methods will berecognized by those skilled in the art.

The multi-segment support member embodiments described above aresuitable for use in the prosthetic valves described herein. Additionalstructures are also possible, and several are described below. Forexample, in reference to FIGS. 9A-B, an alternative support member isillustrated. The alternative support member is a tubular member that iscapable of radial expansion caused by forced foreshortening. As notedearlier herein, several structures and/or methods are available that arecapable of this form of transformation, one of which is described inFIGS. 9A-B. An axially activated support member 150 includes a generallytubular body member 152 formed of a matrix of flexible struts 154. Inthe embodiment shown in the Figures, the struts 154 are arranged incrossing pairs forming an “X” pattern, with the ends of a first crossingpair of struts being connected to the ends of a second crossing pair ofstruts by a band connector 156, thereby forming a generally cylindricalmember. Additional generally cylindrical members are incorporated intothe structure by interweaving the struts contained in the additionalcylindrical member with the struts included in the first cylindricalmember. An axial member 158 is connected to two opposed band connectors156 located on opposite ends of the structure. When the axial member 158is decreased in length, as shown in FIG. 9B, the support member 150 isexpanded to a large diameter state, accompanied by a degree oflengthwise foreshortening of the support member. When the axial member158 is increased in length, as shown in FIG. 9A, the support member 150is contracted to a smaller diameter state, accompanied by a degree oflengthening of the support member. The expanded state may be used whenthe support member is deployed in a body lumen, and the contracted statemay be used for delivery of the device. A valvular body, as describedabove, may be attached to the internal or external surface of thesupport member.

Another support member is shown in FIGS. 10A-J. In this alternativeembodiment, the support member comprises a multiple panel hinged ringstructure 170. The multiple panel hinged ring structure includes threecircumferential rings 172 interconnected by three longitudinal posts174. More or fewer rings and/or posts may be used. Each ring structure,in turn, is composed of a plurality of curved panels 176, each connectedto its adjacent panel by a junction member 178, such as a polymericmembrane hinge. The individual panels 176 have a curvature 180 about theaxis of the device as well as a curvature 182 in the transversedirection. (See FIG. 10E). A coating material 184 maintains the panelsin relation to one another, as well as providing a foldable junction186. The curvature of the panels in conjunction with the coating 184maintains the ring structure in the expanded condition, as shown inFIGS. 10A, 10C, and 10D. The foldable junctions 186 are rotated totransform the structure from an expanded state 188 for deployment, to acontracted state 190 for delivery. (See FIG. 10E-J). A valvular body, asdescribed elsewhere herein, may be attached to the internal or externalsurface of the support member.

In still another alternative embodiment, as shown in FIGS. 11A-C, thesupport member comprises a collapsing hinged structure 200. Thecollapsing hinged structure shown in the Figures includes twenty-fourpanels 202 arranged peripherally around the generally tubular structure,each panel having a tab 204 on its edge that overlaps and engages amating tab 206 on the opposed edge of the adjacent panel, interlockingthe adjacent panels. More or fewer panels are possible. An elasticmembrane 208 is attached to an external surface of adjacent panels andprovides a force biasing the adjacent panels together to assist the tabsin interlocking each adjacent pair of panels. Preferably, the elasticmembrane 208 is attached to the main body of each panel 202, but not atthe opposed edges. Thus, the tabs 204, 206 may be disengaged and thepanels 202 rotated to form a vertex 210 at each shared edge, therebydefining a multi-vertex “star” shape that corresponds with thecontracted state of the support member. The support member 200 istransformed to its expanded state by applying an outward radial forcethat stretches the elastic membrane 208 and allows the tabs 204, 206 tore-engage. A valvular body, as described elsewhere herein, is attachedto the internal or external surface of the support member.

All of the foregoing support members may be incorporated in a prostheticvalve, as described above, by attaching a valvular body to the externalor internal surface of the support member. In the alternative, all ofthe foregoing support members may be utilized without a valvular body toprovide a support or scaffolding function within a body lumen, such as ablood vessel or other organ. For example, the multi-segment,multi-hinged support member may be used as a scaffolding member for thetreatment of abdominal aortic aneurisms, either alone, or in combinationwith another support member, graft, or other therapeutic device. Othersimilar uses are also contemplated, as will be understood by thoseskilled in the art.

Moreover, several additional features and functions may be incorporatedon or in the prosthetic valve or its components, including the supportmember and the valvular body. For example, one or more anchoring membersmay be formed on or attached to any of the above-described supportmember embodiments. Each anchoring member may comprise a barb, a tooth,a hook, or any other member that protrudes from the external surface ofthe support structure to physically engage the internal wall of the bodylumen. An anchoring member may be selectively engageable, such as by anactuator, or it may be oriented so as to be permanently in its engagedstate. Alternatively, the anchoring member may comprise an apertureformed in the support structure that allows tissue to invaginatetherethrough. One example of an anchoring member is illustrated in FIGS.13B and 13C, where a barb 358 is shown extending from the surface of acontracted prosthetic valve 30. The barb 358 may be deflected inwardwhile the prosthetic valve is retained in the delivery device. See FIG.13C. Then, upon deployment, the barb 358 is released and extendsradially outward to engage the surface of the body lumen or othertissue. As noted above, other anchoring members and mechanisms are alsocontemplated for use with the devices described herein.

The prosthetic heart valves and support members described herein providea number of advantages over prior devices in the art. For example, theprosthetic heart valves are able to be transformed to a contracted stateand back to an expanded state without causing folding, tearing,crimping, or otherwise deforming the valve leaflets. In addition, unlikeprior devices, the expanded state of the current device has a fixedcross-sectional size (e.g., diameter) that is not subject to recoilafter expansion. This allows the structure to fit better at itstreatment location and to better prevent migration. It also allows thevalvular body to perform optimally because the size, shape andorientation of the valve leaflets may be designed to a known deploymentsize, rather than a range. Still further, because the expanded state ofthe support structure is of a known shape (again, unlike the priordevices), the valve leaflets may be designed in a manner to provideoptimal performance.

B. Delivery Devices and Methods of Use

Devices for delivering a prosthetic valve to a treatment location in abody lumen are described below, as are methods for their use. Thedelivery devices are particularly adapted for use in minimally invasiveinterventional procedures, such as percutaneous aortic valvereplacements. FIGS. 14A and 15A illustrate two embodiments of thedevices. The delivery devices 300 include an elongated delivery catheter302 having proximal 304 and distal ends 306. A handle 308 is provided atthe proximal end of the delivery catheter. The handle 308 may beprovided with a knob 310, an actuator, a slider, other control members,or combinations thereof for controlling and manipulating the catheter toperform the prosthetic valve delivery procedure. A retractable outersheath 312 may extend over at least a portion of the length of thecatheter. Preferably, a guidewire lumen extends proximally from thedistal end of the catheter. The guidewire lumen may extend through theentire length of the catheter for over-the-wire applications, or theguidewire lumen may have a proximal exit port closer to the distal endof the catheter than the proximal end for use with rapid-exchangeapplications. The distal portion 306 of the catheter includes a carrieradapted to receive and retain a prosthetic valve in a contracted state,and to deploy the prosthetic valve at a treatment location within a bodylumen.

Turning first to FIGS. 12A-F, a first embodiment of a distal portion 306of a prosthetic valve delivery device is shown. The device 300 includesa delivery tube 320 having three longitudinal slots 322 at its distalend, and a gripper 324 having a longitudinal shaft 326 and three fingers328 that extend longitudinally from the distal end of the gripper. Moreor fewer longitudinal slots may be included on the delivery tube, andmore or fewer fingers may be provided on the gripper. Preferably, thedelivery tube 320 has the same number of longitudinal slots, and thegripper 324 includes the same number of fingers, as there are segmentson the prosthetic valve to be delivered. The longitudinal slots 322 onthe distal end of the delivery tube are equally spaced around theperiphery of the tube. Similarly, as viewed from the distal end of thegripper 324, the fingers 328 are arranged in an equi-spaced circularpattern. For example, in the case of three fingers, all three areequally spaced apart on an imaginary circle and are separated from eachother by 120°. In the case of four fingers, the fingers would beseparated from each other by 90°, and so on.

The gripper 324 is slidably and rotatably received within the deliverytube 320, and the delivery tube is internal of the outer sheath (notshown in FIGS. 12A-F). The outer sheath is retractable to expose atleast the longitudinal slots 322 on the distal portion of the deliverytube. The gripper 324 is able to be advanced at least far enough toextend the fingers 328 distally outside the distal end of the deliverytube.

In alternative embodiments of the above delivery device, the gripperfingers 328 may comprise wires, fibers, hooks, or other structuralmembers extending distally from the distal end of the gripper. Asdescribed below, a primary function of the fingers is to retain aprosthetic valve on the distal end of the gripper, and to restrainsegments of the support member of the valve in an inverted state.Accordingly, any of the above (or other) structural members able toperform the above function may be substituted for the fingers describedabove.

The delivery device 300 is particularly adapted for use in a minimallyinvasive surgical procedure to deliver a multi-segment prosthetic valve30, such as those described above, to a body lumen. To do so, theprosthetic valve 30 is first loaded into the delivery device 300. FIGS.12A-F illustrate the case of a prosthetic valve having a three segmentsupport member. The prosthetic valve 30 is loaded into the deliverydevice 300 by first inverting the three panels 36 to produce a threevertex structure. Inverting of the prosthetic valve panels may beperformed manually, or by using an inverting tool. The prosthetic valve30 is then placed onto the distal end of the gripper 324, which has beenpreviously extended outside the distal end of the delivery tube 320,with each of the three fingers 328 retaining one of the inverted panels36 in its inverted position. (See FIG. 12A). The gripper 324 and fingers328, with the prosthetic valve 30 installed thereon, are then retractedback into the delivery tube 320. During the retraction the gripper 324and fingers 328 are rotationally aligned with the delivery tube 320 suchthat the three vertices of the prosthetic valve align with the threelongitudinal slots on the distal end of the delivery tube. (See FIG.12B). When the gripper 324 and fingers 328 are fully retracted, each ofthe three vertices of the prosthetic valve extends radially outside thedelivery tube through the longitudinal slots 322. (See FIG. 12C). Thegripper 324 is then rotated relative to the delivery tube 320, whichaction causes each of the folded segments of the prosthetic valve 30 toengage an edge of its respective delivery tube slot. (See FIG. 12D).Further rotation of the gripper 324 relative to the delivery tube 320causes the folded segments to curl back toward the longitudinal axis ofthe prosthetic valve internally of the delivery tube, creating threelobes located fully within the delivery tube 320. (See FIG. 12E). Theprosthetic valve 30 is thereby loaded into the delivery device 300. Theouter sheath is then advanced over the distal portion of the catheter,including the delivery tube, to prepare the delivery device for use.

The prosthetic valve 30 is delivered by first introducing a guidewireinto the vascular system and to the treatment location of the patient byany conventional method, preferably by way of the femoral artery.Optionally, a suitable introducer sheath may be advanced to facilitateintroduction of the delivery device. The delivery catheter 302 is thenadvanced over the guidewire to the treatment location. The outer sheath312 is then retracted to expose the delivery tube 320. The gripper 324is then rotated relative to the delivery tube 320 (or the delivery tuberotated relative to the gripper), thereby causing the folded panels ofthe prosthetic valve 30 to uncurl and to extend radially outward throughthe longitudinal slots 322 of the delivery tube 320. The delivery tube320 is then retracted (or the gripper advanced) to cause the prostheticvalve 30 (restrained by the fingers 328) to advance distally out of thedelivery tube. The gripper 324 is then retracted relative to theprosthetic valve 30, releasing the prosthetic valve 30 into thetreatment location. (See FIG. 12F). Preferably, the inverted panels 36then revert to the expanded state, causing the valve to lodge againstthe internal surface of the body lumen (e.g., the aortic valve root oranother biologically acceptable aortic position). Additional expansionof the prosthetic valve may be provided, if needed, by a suitableexpansion member, such as the expansion balloon or the expanding meshmember described elsewhere herein, carried on the delivery catheter 302or other carrier.

Turning to FIGS. 13A-E, another embodiment of a distal portion of aprosthetic valve delivery device is shown. The distal portion of thecatheter 302 includes a restraining sheath 340, an orientation sheath342, a plurality of grippers 344, an expander 346, and a plurality ofstruts 348. Each of the grippers 344 includes a wire 350 riding within atube 352, and a tip 354 at the distal end of the tube. The wire 350 ofeach gripper 344 has an end portion 356 formed to engage the vertex of aprosthetic valve support member 32 having multiple segments, and toselectively restrain the prosthetic valve 30 in a contracted state. (SeeFIG. 13B). The expander 346 is adapted to selectively cause the grippers344 to expand radially outwardly when it is actuated by the user by wayof an actuator 310 located on the handle 308.

The prosthetic valve 30 may be loaded into the delivery device 300 bycontracting the prosthetic valve (either manually or with an invertingtool) by inverting each panel 36 and then attaching each vertex to arespective end portion 356 of the wire contained on each gripper 344 onthe delivery device. The gripper wires 350 receive, retain, and restrainthe prosthetic valve 30 in its contracted state. The gripper 344assembly having the prosthetic valve 30 installed is then retracted intoeach of the orientation sheath 342 and the restraining sheath 340 toprepare the device for insertion into the patient's vasculature. Thedevice is then advanced over a guidewire to a treatment location, suchas the base annulus of the native aortic valve. (See FIG. 13E). Therestraining sheath 340 is then retracted to allow the prosthetic valve30 to partially expand (e.g., to about 85% of its full transversedimension), where it is constrained by the orientation sheath 342. Theprosthetic valve 30 is then finally positioned by manipulation of thegrippers 344, after which the orientation sheath 342 is retracted andthe grippers 344 released. The prosthetic valve 30 then lodges itself inthe treatment location.

Other embodiments of the delivery device are illustrated in FIGS. 14A-Eand 15A-B. As shown in those Figures, the distal portion 306 of thecatheter includes one or more restraining tubes 370 having at least one(and preferably two) adjustable restraining loops 372. In the embodimentshown in FIGS. 14A-E, the device is provided with one restraining tube370 and two restraining loops 372. In the embodiment shown in FIGS.15A-B, the device is provided with three restraining tubes 370 and tworestraining loops 372. The restraining tube(s) 370 extend distally froma catheter shaft 374 out of the distal end of the delivery device, andeach restraining loop 372 is a wire or fiber loop that extendstransversely of the restraining tube 370. Each restraining loop 372 is aflexible loop capable of selectively restraining a contracted prostheticvalve. The restraining loops 372 may be selectively constricted orreleased by a control member, such as a knob 310, located on the handle308 of the device. A retractable outer sheath 376 covers the distalportion of the catheter.

The prosthetic valve 30 may be loaded onto the delivery device bycontracting the prosthetic valve (either manually or with an invertingtool) into its contracted state, for example, by inverting each panel 36and curling each inverted panel into a lobe. The contracted prostheticvalve is then placed onto the restraining tube(s) 370 and through theone or more restraining loops 372. (See, e.g., FIG. 14B). The loops 372are constricted around the contracted prosthetic valve 30, therebyrestraining the prosthetic valve in its contracted state. The outersheath 376 is then advanced over the prosthetic valve and therestraining tube(s) to prepare the delivery device for use. (See FIG.14C). The device is then advanced over a guidewire to a treatmentlocation, such as the base annulus of the native aortic valve. (See FIG.14D). The restraining sheath 376 is then retracted to expose thecontracted prosthetic valve 30. The restraining loops 372 are released,such as by rotating the control knob 310, thereby releasing theprosthetic valve 30 and allowing it to self-expand. (See FIG. 14E). Theprosthetic valve 30 then lodges itself in the treatment location. Anexpansion member may be advanced to the interior of the prosthetic valveand expanded to provide additional expansion force, if needed ordesired.

Another embodiment of the delivery device is shown in FIGS. 16A-B. Asshown there, the distal portion of the catheter includes a gripper 400that includes a base portion 402 having three restraining members 404extending distally from the gripper base. In the embodiment shown, eachof the restraining members 404 includes a wire loop 406 extendingthrough a sleeve 408, with both the sleeve and the wire loop extendingdistally from the gripper base 402. The wire loops 406 also extendproximally of the gripper base 402, which is provided with a lumen 410corresponding with each of the wire loops 406, thereby allowing thegripper base 402 and the sleeves 404 to slide relative to the wire loops406. A delivery tube 412 may also be provided. As shown in the Figures,the gripper 400 is slidably received within the delivery tube 412, andthe tube has three longitudinal slots 414 corresponding with the threerestraining members 404 on the gripper assembly. An atraumatic tip 416or nosecone is attached to a central shaft 418 that extends through thecenter of the catheter 302 internally of the gripper 400 and thedelivery tube 412. The central shaft 418 includes a guidewire lumen toaccommodate a guidewire used to assist deployment of the deliverydevice.

Although the device shown in the Figures includes three restrainingmembers 404, fewer or additional restraining members may be used. Onefunction of the restraining members is to retain a prosthetic valve onthe distal end of the delivery device, and to selectively maintain thevalve in a contracted state. In the preferred embodiment, the number ofrestraining members will coincide with the number of segments (e.g.,panels) included on the prosthetic valve.

Turning to FIG. 16A, the delivery device 300 is shown with the deliverytube 412 and gripper 400 retracted relative to the wire loops 406,thereby allowing the distal ends 420 of the wire loops to extend freelyaway from the central shaft 418. The delivery device in this conditionis adapted to have a prosthetic valve installed onto the device. To doso, the prosthetic valve 30 is first placed over the distal end of thedevice and the panels 36 of the valve are inverted. Alternatively, thevalve panels 36 may be inverted prior to or simultaneous with placingthe valve over the distal end of the delivery device. The wire loops 406are then placed over the inverted panels 36, and the gripper 400 isadvanced to cause the sleeves 408 to physically engage the invertedpanels 36. See FIG. 16B. The sleeves 408 have sufficient strength tomaintain the prosthetic valve panels in their inverted state. Thedelivery tube 412 may then be advanced over the distal end of thedevice, with the valve panel vertices extending out of the longitudinalslots 414 formed on the delivery tube 412. The gripper 400 may then berotated relative to the delivery tube (or vice versa) to contract thepanel vertices within the interior of the delivery tube and to therebyprepare the device for delivery of the prosthetic valve. The valve isdelivered in the same manner described above in relation to the deviceshown in FIGS. 12A-E.

As noted, each of the foregoing delivery devices is suitable for use indelivering a prosthetic heart valve or a support member, such as thosedescribed herein. In the case of a prosthetic heart valve, the deliverymethods may be combined with other treatment devices, methods, andprocedures, particularly procedures intended to open or treat a stenoticheart valve. For example, a valvuloplasty procedure may be performedprior to the prosthetic heart valve deployment. The valvuloplastyprocedure may be performed using a conventional balloon or a cuttingballoon adapted to cut scarred leaflets so that they open more easily.Other treatments, such as chemical treatments to soften calcificationsor other disorders may also be performed.

Each of the foregoing delivery devices may be provided with a tetherconnecting the delivery device to the prosthetic valve or supportmember. The tether is preferably formed of a material and has a sizesufficient to control the prosthetic valve or support member in theevent that it is needed to withdraw the device during or afterdeployment. Preferably, the tether may be selectably disengaged by theuser after deployment of the device.

Turning to FIGS. 17A-B and 18A-D, two types of expansion members areprovided for performing dilation functions in minimally invasivesurgical procedures. The expansion members may be used, for example, inprocedures such as angioplasty, valvuloplasty, stent or other deviceplacement or expansion, and other similar procedures. In relation to thedevices and methods described above and elsewhere herein, the expansionmembers may be used to provide additional expansion force to the supportmembers used on the prosthetic valves described herein.

In one embodiment, illustrated in FIGS. 17A-B, the expansion member 430includes three elongated inflation balloons 432 a-c oriented about alongitudinal axis 434. Each inflation balloon 432 is connected at itsproximal end by a feeder lumen 436 to a central lumen 438 that providesfluid communication between the inflation balloons 432 a-c and a sourceof inflation media associated with a handle portion 308 of a catheter.The central lumen itself is provided with a guidewire lumen 440 to allowpassage of a guidewire through the expansion member 430. A flexiblemember 442 is attached to the distal end of each of the inflationballoons 432 a-c, and also includes a guidewire lumen. Although theexpansion member shown in the Figures includes three inflation balloons,fewer or more balloons are possible. Moreover, each of the individualballoons may be inflated separately, all inflated together, or anycombination thereof to obtain a desired force profile. The multipleinflation balloon structure provides a number of advantages, includingthe ability to provide greater radial forces than a single balloon, andthe ability to avoid occluding a vessel undergoing treatment and toallow blood or other fluid to flow through the device.

In an alternative embodiment, shown in FIGS. 18A-D, the expansion member450 comprises a flexible, expandable mesh member 452. The expandablemesh member 452 includes a shaft 454 and a cylindrical woven mesh member452 disposed longitudinally over the shaft. A distal end 456 of thecylindrical mesh member is attached to the distal end 458 of the shaft.The proximal end 460 of the cylindrical mesh member is slidably engagedto the shaft by a collar 462 proximally of the distal end 456. As thecollar 462 is advanced distally along the shaft 454, the body of thecylindrical mesh member 452 is caused to expand radially, therebyproviding a radially expandable member.

The preferred embodiments of the inventions that are the subject of thisapplication are described above in detail for the purpose of settingforth a complete disclosure and for the sake of explanation and clarity.Those skilled in the art will envision other modifications within thescope and spirit of the present disclosure. Such alternatives,additions, modifications, and improvements may be made without departingfrom the scope of the present inventions, which is defined by theclaims.

What is claimed is:
 1. An apparatus for delivering a prosthetic heartvalve to a body lumen, comprising: a delivery catheter comprising a tubeand a gripper, the tube having a plurality of slots and the gripperhaving a plurality of fingers; a prosthetic heart valve having a supportstructure comprising a plurality of folded panels and being coupled, ina contracted state, with the gripper; wherein relative rotation betweenthe tube and the gripper causes the plurality of folded panels to movethrough and radially extend outward from the plurality of slots of thetube, wherein longitudinal movement of the gripper relative to the tubecauses the folded panels to slide out of the slots, and wherein relativemotion between the gripper and the prosthetic heart valve causes theprosthetic heart valve to be released from the fingers of the gripper.2. The apparatus of claim 1, wherein the prosthetic heart valve isbiased to revert to the expanded state after release from the gripper.3. The apparatus of claim 1, further comprising an expansion member forexpansion of the prosthetic heart valve after release from the gripper.4. The apparatus of claim 3, wherein the expansion member is a meshmember.
 5. The apparatus of claim 3, wherein the expansion membercomprises a balloon.
 6. The apparatus of claim 1, further comprising asheath slidable over the slots of the tube.
 7. The apparatus of claim 1,wherein the gripper is an elongate member defining a longitudinal axis,and each of the plurality of fingers extends from a first end of thegripper generally parallel to the longitudinal axis.
 8. The apparatus ofclaim 1, further comprising a handle located at a proximal end of thedelivery catheter, the handle adapted to control the relative rotationand the longitudinal motion of the tube and the gripper.
 9. Theapparatus of claim 1, wherein the gripper is slidably and rotatablereceived within the tube.
 10. The apparatus of claim 1, wherein thedelivery catheter comprises an atraumatic nosecone configured to enhancethe ability of the delivery catheter to pass through vasculature of thepatient.
 11. An apparatus for delivering a prosthetic heart valve to abody lumen, comprising: a delivery catheter comprising a tube andgripper, the tube having a plurality of slots and the gripper having aplurality of fingers; a prosthetic heart valve having a supportstructure comprising a plurality of folded panels and being coupled, ina contracted state, with the gripper; wherein relative rotation betweenthe tube and the gripper causes the plurality of folded panels to movethrough and radially extend outward from the plurality of slots of thetube, wherein longitudinal movement of the gripper relative to the tubecauses the folded panels to slide out of the slots, wherein relativemotion between the gripper and the prosthetic heart valve causes theprosthetic heart valve to be released from the fingers of the gripper,and wherein the tube comprises only three slots, the gripper comprisesonly three fingers, and the prosthetic heart valve comprises only threepanels, each panel being metallic.